I did the mods this weekend and to my (very) untrained ears it sounds really good. Of course i have never heard other "really good" studios to compare. Anyway i'm satisfied with the result.

I tested it against my RME ADI8-pro and it has much better frequency response, sounds more full in the low and high end.

I replaced most caps with Panasonic FM's and replaced the 2 ceramic disc caps for Panasonic ECQ-P 0.1uf. Upped the power supply caps from 2200uf to 2700uf. replaced most tantalums with FM 47uf and replaced the opamp with the 2 ADA4898-1 in the brown dog adapter. changing the opamp became easier than i expected. Of course i destroyed the original op amp but i was not going to use that either way. I also bypased the 47uf that replaced the tantalums with Panasonic ECQ-P 0.1uf in the back of the board.

When i have a chance to order some of the high end 0.1uf caps i'll try them there to see what difference i get.
Can anyone recommend other bypass caps besides the MIT that jim recommended already?

I forgot to order the 100uf caps but didn't realize it until i had taken one out next to the ADC chip so i put in an extra 470uf one i had. I don't know if this was the right thing to do based on the design and the specs of the DAC chip. If it's not right and i should go back to 100uf please someone let me know.

[QUOTE=Jim Williams;3596596]I installed the Analog Devices ADA4898-1 on a Brown Dog 031101A header and put it in. It sounds great. Much better than the National LME49722MA. It has better low end depth and extension, much better top end details.

I may have found an alternative which negates the need for a brown dog. Having not tried the 4898 i cannot do a direct comparison but it seems to be a vast improvement already. It was fitted by my neighbour Sven Olsen (chillisoundworks@ymail.com) I've yet to upgrade the caps so it's not fully customised yet. The replacement part is an Analogue Devices AD8599 which isn't as easily available apparently, unless you have a trade account with Analogue Devices. It's a dual chip so it fits directly surface mounted onto the board without the need for a brown dog. Here's a pic for anyone who's interested. I really need to get the brown dog version as well for a decent comparison. Waiting for the chips to arrive now.

The AD8599 is a very low noise audio dual opamp. I use them for apps that folks want quiet yet soft tops. It is slower, a 15 v/us slew rate vs 65 v/us slew rate for the ADA4898. It also does not have the output current either.

I find it to sound soft with transients, less bass and top end extension than the 4898.The LME49722 is a better choice if you don't want to mess with adaptors.

The AD8599 is a very low noise audio dual opamp. I use them for apps that folks want quiet yet soft tops. It is slower, a 15 v/us slew rate vs 65 v/us slew rate for the ADA4898. It also does not have the output current either.

I find it to sound soft with transients, less bass and top end extension than the 4898.The LME49722 is a better choice if you don't want to mess with adaptors.

A single version, the AD8597 is also available.

Jim Williams
Audio Upgrades

Thanks for the info. Perhaps i should have hung on and got the part you recommended. Or maybe i could get another convertor! If only i had more digital outs on my multiface!

I'm interested in this converter!
My question is, I'm planing to connect it to a speaker selector that has balanced inputs. So that means I'm gonna have to get rca to xlr cables. Is there a downside to this? Will it work properly? Or do I need to get a unbalanced to balanced converter?

I'm interested in this converter!
My question is, I'm planing to connect it to a speaker selector that has balanced inputs. So that means I'm gonna have to get rca to xlr cables. Is there a downside to this? Will it work properly? Or do I need to get a unbalanced to balanced converter?

[QUOTE=Jim Williams;4207509]The AD8599 is a very low noise audio dual opamp. I use them for apps that folks want quiet yet soft tops. It is slower, a 15 v/us slew rate vs 65 v/us slew rate for the ADA4898. It also does not have the output current either.

I find it to sound soft with transients, less bass and top end extension than the 4898.The LME49722 is a better choice if you don't want to mess with adaptors.]

I have tried the LM's from National and unfortunately to my ears find them very to extremely clean, but also 'lifeless' IE. bit plain with no musical sparkle where present/needed.

I have some of Your recommended AD single chip's on sample order with Analog and look very much forward to a listen to that solution. Many thanks for making me/us aware of this option.

I do find with the AD8599 adaptation, a sound image very close to Your quote. I have for other applications had very, very good results with the this chip. What is also apparent is that the unit quite desperately is in need of better capacitors in the signal path... (bass is unpresent and resolution needs improving - have a grim suspicion with the tantalums for starters). So hopefully owl is up for that 'Doctoring' as well as Your recommended AD chips on the nice Brown dog adaptor.

You gotta catch it on sale...there may be a discount code...I dunno...I got mine with a code and it reduced the price.

ohh, I see...well anybody gotta discount code they are willing to offer up? I tried the source code that was mentioned but it did not work.
It would much be appreciated as this thing just fits into my budget, (with cables and replacement chips etc...).

Okay,even $105 has got my attention. So ,I have zilch ability with modding anything and I am wondering,how does this little puppy sound as is? If the mods do make that much of a difference is anyone here with skill(besides Jim,of course Jim would be good too)willing to do a job for some $cratch? Also,IF the answer is no(so be it) do you guys think that I would hear any major improvement running from my M-Audio 24/96 via the spdif cable with this box as is? It's almost worth the $105 just to see.....I said ALMOST!

Okay,even $105 has got my attention. So ,I have zilch ability with modding anything and I am wondering,how does this little puppy sound as is? If the mods do make that much of a difference is anyone here with skill(besides Jim,of course Jim would be good too)willing to do a job for some $cratch? Also,IF the answer is no(so be it) do you guys think that I would hear any major improvement running from my M-Audio 24/96 via the spdif cable with this box as is? It's almost worth the $105 just to see.....I said ALMOST!

Okay,even $105 has got my attention. So ,I have zilch ability with modding anything and I am wondering,how does this little puppy sound as is? If the mods do make that much of a difference is anyone here with skill(besides Jim,of course Jim would be good too)willing to do a job for some $cratch? Also,IF the answer is no(so be it) do you guys think that I would hear any major improvement running from my M-Audio 24/96 via the spdif cable with this box as is? It's almost worth the $105 just to see.....I said ALMOST!

Has anyone here tried the resistor mods yet for the MCM $79 DAC? Maybe someone here can explain what jumping those two resistors does(r11 & r14), and if it is even necessary with the AD4898 op amp Jim Williams suggested. I can't find anything other than the PDF on the Beresford site.

jim, what do you think the likelihood is of an m-audio fw1814's modifications being the same (or similar) to this unit's? on the other hand, do you think the components and/or mod's that it needed would be obvious? has anyone here (outside of bla) successfully attempted to upgrade one? i'm thinking of maybe practicing on this box. and please excuse the naivete of my questions .

I don't have the soldering to attempt to MOD this DAC. (I can barely fix cables) I need a good D/A and I was looking at an older Lucid DA 9624 for like $350 used, or one of these modded. Anybody know how those two would compare ?

I was checking Ebay for one of these models premodded and was sure I would find one.... I don't think I had any luck though. I'm kind of nervous about buying from that one beresfoot overseas site.

If anybody has one of these they're already modded I'd be interested in buying it .

Not sure what the Lucid sounds like,.. But the MCM killed RME even stock..with the mods it sounds great..

I still like my D/A on the Dangerous D-Box better.. But something like MOTU or RME I think this MCM will beat it.

If your trying to be any kind of audio engineer You need to learn to Solder.. It's not hard. But learning just that then repairing or fixing things will make you a better engineer.. It's amazing how the audio side will improve just from you doing all your own cables and learning to fix things..

I was preached to many years ago for the same thing..And it did pay off.

I plugged in my MCM DAC yesterday and listened to a couple of records... first impressions are that it's a decent DAC - on par with my M-Audio Profire 2626 and the Presonus Central Station I used to have. It does not sound as good as my Lavry DA10 or Apogee Trak2 DAC w/option, but it was only $85 after all.

A question for Jim Williams or any others that may have analyzed the circuit more than I have:

I see the 4558 opamp on there, and also the LM386's. The DAC has a variable output and a fixed output, and the volume control affects the variable out and the headphone out. Is the variable out fed by the 386's? Is the 4558 for the fixed output only? I looked at the board but eye tracing circuits on double-layer SMD boards is pretty difficult and my scope is at my other workplace across town...

I plugged in my MCM DAC yesterday and listened to a couple of records... first impressions are that it's a decent DAC - on par with my M-Audio Profire 2626 and the Presonus Central Station I used to have. It does not sound as good as my Lavry DA10 or Apogee Trak2 DAC w/option, but it was only $85 after all.

A question for Jim Williams or any others that may have analyzed the circuit more than I have:

I see the 4558 opamp on there, and also the LM386's. The DAC has a variable output and a fixed output, and the volume control affects the variable out and the headphone out. Is the variable out fed by the 386's? Is the 4558 for the fixed output only? I looked at the board but eye tracing circuits on double-layer SMD boards is pretty difficult and my scope is at my other workplace across town...